Sostenuto piano



Novr 4, 1930,

's. COOPER 1,780,670

' SOSTENUTO PIANO Filed March 12, 1929 2 Sheets-Sheet l awueutoz S.COOPER SOSTENUTO PIANO Nov. 4, 1930.

Filed March 12, 1929 2 Sheets-Sheet 2 Qwwanfoa: A z'hrazz 6 00 3Patented Nov; 4, 1930 UNITED STATES PATENT OFFICE smon coornn,orrnoomam, imw YORK SOSTENUTO PIANO Application meamreh 12, 1929. Serialno. 846,290.

should be produced for the chord or'passage thus played pianissimo'and,in electric sustes nuto pianos it is especially desirable to be able toplay pianissimo passages with full sostenuto effect. Where the sostenutoefiect is obtained by electro-magnetic means the energy required tomaintain a vibrating string in singing oscillation is very small but, ifthis amount of energy is relied upon to. initiate the string vibrationswithout resortto the hammer, considerable time will elapse before thestring retains its proper amplitude of vibration by the overcoming ofits inertia.

-Moreover, if only weak impulses are used at first the string is apt tobe thrown into nodal vibrations with the result that it does not vibrateto produce its fundamental tone but only produces overtones or partialswhich may cause very unpleasant eflect on the ear. One important 0 ectofthe present invention is, therefore, to provide improvedelectro-magnetic mechanism by which the musician, inplaying, is enabledto immediately overcome the inertia of the string or strings and toinitiate the desired amplitude ofivibration as quickly as is wanted andyet afterward have control of the amount of electrical energy so as tovary the amplitude-of the string vibrations.

A second important object ofthe invention is to provide improvedelectro-magnetic means in such a piano as will initiate imme diatelyfull electro-magnetic efie'ct even though the key be touched only hardenough to produce a pianissimotone. e

A third important object of the invention is to provide, in an electricsostenuto piano,

electro-magnetic means whereby depression of a key will bringimmediately full magnetic force on the string controlled by the key andwill be automatically followed by continuing and gradually decreasingelectro magnetic impulses as soon as the string has been given the fullamplitude of vibration desired to be magnetically-produced.

A fourth important object of the invention is to provide, in such apiano, improved elec o0 tro-magnetic sostenuto means in which themagnetic strength may be regulated at the will of the musician.

With the above and other objects in view as will be hereinafterapparent, the invention consists in general of certain novel details ofconstruction and combinations of parts hereinafter vfully described,illustrated in the accompanying drawings and specifically cl aimed.

In the accompanying drawings like characters of reference indicate likeparts in the several views, and: 7 I Figure 1 1s a diagrammatic view ofa single key, ts strmg and the improved electro 7 magnetic means, thekey being shown in fu1ly raised or. normal position.

. Figure 2 is a view of the key and circuit closers showing the relationof the parts under slight depression of the key.

Figure 3 is a view similar to Fi'gure 2 with the key further depressed.

Figure 4 is a view similar to Figure 2 with the key almostfullydepressed.

Figure 5 is a view similar to Figure 2 but showing the key fullydepressed and about to rise.

Figure 6 is a perspective detail of a certain camming contact and pinused herein.

In the form of the invention as illustrated in the accompanying drawingsbut one key and its associated parts have been shown but it is obviousthat each key of the piano or a number of keys of such piano are tofunction similarly. The invention is, however, clearly shown by itsassociation with a single key. 7

Bearing this in mind it will be seen that there is. provided a key 10and a string 11 stretched between pegs 12and passing over a. 0

bridge 13, these parts being all of ordinary character. To the string 11adjacent the bridge 13 is attached one side orelement of a modulator 14such as is disclosed in my prior Patent No. 1,598,056. The other side ofthis modulator is connected by a wire 15 with one side of a secondmodulator 16 which is in turn connected by a wire 17 with a suitablesource of current such as the battery 18 which in turn is connected by awire 19 with a spring contact 20 fixed to the underside of the key andengageable, upon depression of the key,-with a fixed springcontact 21secured to some suitable part of the piano. At '22, adjacent the string11, is an electromagnet having one terminal connected by a wire 23 withthe contact 21 and having its other terminal connected by a wire 24 withthe first mentioned side of the modulator 14;. It is to be noted thatboth modulators'14 and 16 constitute variable resistances in whichmovement of one element toward, the other I decreases the reslstance'andmovement of one element away from the other increases the resistance.Beneath the key 10 is fixed a pin 25 which engages the movable member ofmodulator 16 to decrease the resistance upon depression of the key toadesired extent. Also, beneath the key is secured a spring contact finger26 which has adjacent its free end a bend forming a wiping point 27, theextremity of the bend being provided with an angularly disposed camextension 28 -working past apin 29 fixed in the piano frame. By thisarrangement the contact 26 is forced in one direction upon depression ofthe key and in the opposite direction as the key rises. This contact 26is connected by a wire '30 with the wire 24. Fixed to the piano frame isa spring contact 31 which has a wiping point 32 engaged by the point 27upon depression of the key 10 but, due to the cam action of the parts 28and 29, free from such engagement upon This return of the contact 26 toraised position without engagement with the contact 31 is effected byreason of the cam portion 28, which is ofiset to engage the pin 29,conthe key rising.

tacting with the right side. of this pin on. rising from thepositionshown in Figure 5' so that, by reason of the angularity of this camportion, the point 27 will be carried to the right and thus clear thepoint 32 without contacting therewith. This contact 31 is connected by awire 33 with the wire 17.

- Thus the circuit established by contacts 26 and 31 when closed is ashunt circuit around the modulators and sends the full currentof thebattery 18 through the magnet 22.

, I also prefer to insert, in the line 19,-a pedal controlled rheostat34 by means of which the musician may modify the current passing throughthe magnet at will.

Referring to Figures 2 to 5 it will be seen that slight depression ofthe key 10 closes the contacts 26 and 31 and thus imparts a relativelyheavy magnetic pluck to the string. This is immediately broken (Figure3) as the depression of the key continues and next (Figure 4) theresistance of modulator 16 is decreased, this decrease. continuing untilthe key has been fully depressed. Obviously, the extent and duration ofdepression of the key is regulated by the musician so that he may thusproduce a wide range of sostenuto effects. 1

There has thus been provided a simple and efficient device of the kinddescribed and for the purpose specified.

It is obvious that minor changes may be made in the form andconstruction of the invention without departing from the material spiritthereof. It is not, therefore, desired to confine the invention to theexact form herein shown and described, but it is desired 'to include allsuch as properly come within the scope claimed.

Having'thus described the invention, what is claimed as new, is

1. In an electric sostenuto piano, electromagnetic means for imparting apowerful the fundamental note of said string.

, 2. In a electric sostenuto piano, electromagnetic means for initiatinga powerful vibration of the piano string, and other electro-magneticmeans for maintaining the vibration of the string with'a diminishedelectro-magnetic attraction.

3. In a sostenuto piano, a string, an electromagnet adjacent the stringto cause oscillation thereof upon energization, means to pass arelatively high initial current through said magnet, and other means tomaintain a relatively low oscillating current through said' magnet. j

, 4. In a sostenuto piano, a string, an electromagnet adjacent thestring to cause oscillation thereof uponenergization, means to pass arelatively high initial current through said magnet, and other means tomaintain a relatively low oscillating current through said magnet, saidother means being under control of the operator.

5. In a sostenuto piano, a string, an electromagnet adjacent the stringto caus'e'oscillationthereof upon energization, means to pass arelatively high initial current through said magnet, and other means tomaintain a relatively low oscillating current through said magnet, saidother means being under control of the operator so as to increase ordecrease the amplitude of the string vibrations.

6. In an electric sostenuto piano having a string and a key, means forimparting an invibrating the string,

bration of the string to vary the current energizing the electro-magnetto maintain sostenuto tone.

7. In an electric'sostenuto piano having a string and a key, means forimparting an 1nitial' impulse to the string by magnetic attraction, suchmeans acting momentarily and ceasing, and other means actuated by thevibration of the string to vary the current energizing theelec'trc-magnet to maintain sostenuto tone.

-8. In an electric sostenuto piano having a string and a key, means forimparting an initial impulse to the string by magnetic attraction, suchmeans acting momentarily and ceasing, and other means actuated by thevibration of the string to vary the current energizing theelectro-magnet to maintain sostenuto tone, the energy for such othermeans going controlled by pressure on the piano ey. '9. In a pianohaving a string, an electromagnet adjacent said string, means toenergize the magnet to a degree suflicient to impart hammer blow efl'ectto the string, and other means to impart oscillationsto the magnetstrength to maintain the string in vibra tion.

, 10. In a piano having a string, an electromagnet adjacent said string,means to energize the magnet to a degree sufiicient to impart hammerblow eifect to the string, and other means to impart oscillations to themagnet strength to maintain the string in. vibration, said last meansbeing so arranged as to develop the harmonics of the musical notesounded. I

11. In an electric sostenuto piano having a string, a magnet located toinitiate the vibra: tion of the piano string by causing it to sound thefundamental note of the string, and means connected with theelectro-magnet to maintain the vibration of the string and developingthe partial tones in addition to the fundamental note.

12. In an electric sostenuto piano having a string, electro-magneticmeans for initially and means for maintaining the sostenuto tones whichinclude the partials of the note after the string has been caused tovibrate by said electro-magnetic means. y

13. In' an electric sostenutotpiano having a string, electro-magneticmeans for initially vibratingthe string, and means for maintaining thesostenuto tones which include the partials of the note after thestringhas been caused-to vibrate by said electro-magnetic means, saidfirst mentioned means being controlled by the operator as to varying theamplitude of string vibration.

14. In an electric sostenuto piano, electromagnetic means formaintaining string vibration including a variable conducting mediumcontrolled byv the pressure of the piano key.

bration including a variable con a current pulsator actuated by thestring 15. In an electric sostenuto piano, electromagnetic means formaintaining string viucting medium controlled by the pressure of thepiano key, said medium decreasing its electrical resistance withincrease of pressure applied by the key. 16. In an electric sostenutopiano having a string, the combination of a circuit includingvibrations, an electro-magnet for vibrating the string, said pulsatorvarying the electromagnet acting to keep the string in vibration, asource of electric energy, and a switch for closin the circuit by thedepression of the piano ey.

17. In an electric sostenuto piano having a string, the combination of acircuit including a current pulsator actuated by the string vibrations,an electro-magnet for vibrating the string, said pulsator varying theelectro-magnet acting to keep the string in vibration, a source ofelectric energy, a switch for closing the circuit by the depression ofthe piano key, and a shunt circuit for initiating the string vibrationwhich connects the electro-magnet directly with a source of energy.

18. 4 In an electric sostenuto piano having a string, the combination ofa circuit, including a current pulsator actuated by the stringvibrations, an electro-magnet for vibrating the string, said pulsatorvarying the electro-magnet acting to keep the string in vibration, asource of electric energy, a switch for closing the circuit by thedepression of the piano key,

and a shunt circuit for initiating the string vibration which connectsthe electro-magnet directly with a source of energy, said shunt circuitbeing closed for a portion of the movement to depress the piano key.

19. In an electric sostenuto piano having a string, the combination'of acircuit including a current pulsator actuated 'by the string vibrations,an electro-magnet for vibrating the string,-said pulsator varying theelectro magnet acting to keep the string in vibration, a source ofelectric energy, a switch for closing the'circuit by the depression ofthe piano key, and a shunt circuit for initiating the string vibrationwhich connects the electrokey.

- 20. In an electric sostenuto piano, electromagnetic means forinitiating a powerful vib'ration of the piano string, and otherelectromagnetic means for maintaining the Vibration of the string with adiminished electromagnetic attraction so arranged that the initiatingmeans does not repeat when the mai itaining means ceases. v r

21. In an electric sostenuto piano having a string and a key, means forimparting an initial impulse to the string by magnetic attraction, andother means actuated by the vibrationof the string to vary the currentenergizing the electro-magnet to maintain sostenuto tone, the saidinitiating means only functioning when the piano key is being depressed.

' 22. In an electric sostenuto piano having a string, a magnet locatedto initiate the vibration of the piano string by causing it to sound 7the fundamental note of the string, and means connected with theelectro-m'agnet to maintain the vibration of the string and developingthe partial tones in addition to the funda mental note, said initiatingmeans acting only Epon the downward movement of the piano 23. In anelectric sostenuto piano having a string, the combination of a circuitincluding a current pulsator actuated by the string vibrations, anelectro-magnet for vibrating the string, said pulsator varying theelectromagnet acting to keep the string in vibration, a source ofelectric energy, aswitch for closing the circuit by the depression ofthe piano key, and=a shunt circuit for initiating the string vibrationwhich connects the electro-magnet directly with a source of energy, saidshunt circuit being actuated only by the downward motion of the pianokey.

24. In an electric sostenuto piano, electromagnetic means for impartinga powerful momentary impulse to a string to initiate string vibration,and electro-magnetic means for continuing the string vibration by meanscalculated to also develop the harmonics of the fundamental noteof saidstring, said first means being arranged for variation in force under thecontrol of the operator.

25. In an electric sostenuto piano, electromagnetic means for initiatinga powerful vibration of the piano string, and other e1ectr0- magneticmeans for maintaining the vibration of the string with a diminishedelectros V magnetic attraction, said first means being arranged forvariation in force under the control of the operator.

26. In a sostenuto piano, a string, an eleci tromagnet adjacent thestring to cause oscil-' lation thereof upon energization; means to passa relatively high initial current through said magnet, other means tomaintain a rela tively low oscillating current through said magnet, saidother means being under control of the operator so as to increase ordecrease the amplitude of the string vibrations, and a third meanscontrolling the first and second means and arranged to vary the input ofelectric energy to the electro-magnet.

In testimony whereof I afiix m signature.

I SIMON OOPER.

